Method and means for extracting essentials from coffee and other substances



Aprll l, 1930. G. w. TARKINGTON 1,752,761

METHOD AND MEANS FUR EXTRACTING ESSENTIALS FROM COFFEE AND OTHERSUBSTANCES Filed July 5, 1924 I N VEN TOR.

G 14 Tar/ring 70 ATTORNEY.

Patented Apr. 1, 19 30 UNITED STATES PATENT OFFICE enoncn w. raameron,or smvim ram cormuno Application fled Jifly I; 190%. Serial Ilo.784,888.

My invention relates to a device for extractin the essentials fromground coffee and t or substances and its rincipal ob ect 15 to rovidein a device of t is character means r regulating the flow of the extractby antomatic control of the pressures under whlch it is obtained.

With the above and other ob ects in view, In invention consists inproviding a contamer having a bottom member composed of a suitablestrainer or filter medium. An openin in the side of the container admltsair to t e space above the infuslon supported on the filter bottom, anda ga e in connection with the opening automatical y regulates theadmission of air so as to mamtam 1n the space above referred to, apartial vacuum which retards the flow of liquid to a predeterminedextent during the greater part of the :0 operation.

The gage furthermore functions to admit air to the space above thecontents of the container without its passing through the 1nfusion,which is of advantage since aeration of many substances such as coflee,during the of extraction, produces chemical changes detrimental to theflavor of the extract.

By the use of m inventionan extract of full strength and avor is rapidlyproduced without its being contaminated by undesired ingredients of thesubstance under treatment or by the admixture ofsolids capable ofpassing through the interstices of the filtering medium.

The device for carrying my invention into practice, an embodiment ofwhich has been illustrated in the accompanying drawmgs,

0 has many structural advantages which add to its efiiciency andpracticability in use and W111 be fully disclosed in the course of thefollowing description.

In the drawings in the three views of which like parts are similarlydesignated.

Figure 1 represents a sectional elevation of the device embodying myinvention, in the position it occupies in the first stage of the processprior to the delivery of the extract. Figure 2, a similar sectionalelevation of the device in an inverted position abovea vessel in whichthe extract is received; and

Figure 3, a horizontal section in a lane indicated by the line 3-3 inFigure Referring in detail to the drawings, 5 designates a preferablycylindrical container having a mouth defined by an inwardly tapering rim6 the edge of which is ring-beaded to prevent wear or injury to thefilter medium drawn across the mouth.

The filter medium 7 consists of a suitable fabric, preferably a piece ofwhite cloth, which is drawn taut over the circumferential edge of themouth of the container and secured in position by a sliding ring 8 whichfits snugly upon the cylindrical wall of the container. 7

The upper edge of the ring is ring-beaded or otherwise flanged as at 9,so that by engagement with the rim of a vessel 10 upon whlch the deviceis sup orted in an inverted position as shown in igure 2, it madetermine the depth to which the mouth of t e container rojects in thevessel and thereby uge the height to which the vessel is fille with theextract delivered through the filter. cloth.

The container has in its circumferential wall an air-inlet preferablyrovided through the medium of a duct. 12 0? U-shaped form, one le to wit'n a short distance from its mouth, and the other leg of which projectsoutside the container in spaced relation to the wall'thereof to providea handle which facilitates manipulation of the device. A grip 13 ofinsu! lating material fitted around the handle protects the hand of theuser from the heated aluminum or other metal of which the device is madein preference to other materials.

The gage of the device mentioned hereinbefore, consists of an open endedtube 14 coaxial with the inner member of the air duct and projectingthrough an aperture in the lower portion of the duct, the upper andlower ends of the tube being positioned respectively below the upper endof the duct and in spaced relation to the bottom of the container. y

In the operation of my invention, the container is partially filled withwater heated to of which extends inside the container' the boilingpoint, together with a measured quantity of coffee or other substancefrom which an extract is desired.

The cloth filter is then secured over the mouth of the container in themanner hereinbefore described, after which the device is graduallyturned to the reversed position overa cup or other receiver asillustrated in Figure 2.

In filling the container, care should be taken to not have liquid enterthe air duct and to keep the level of the liquid below the upper end ofthe gage tube 14.

As soon as the container is placed in its reversed position, theinfusion contained therein seeks a new level, leaving a space 15 in theupper portion of the device filled with air at less than atmosphericpressure.

The liquid which was contained in the gage tube passes through the newlower end thereof and is met by the liquid rising in the air duct.

:The liquid rising in the air duct by the hydrostatic head indicated inFigure 2 of the drawing by the. broken line 16, enlarges the space 15 inthe upper portion of the container and thereby rarefies the air in saidspace until the liquid head and the air pressure in said space balancethe outside at mospheric pressure. At the same time, however, the flowof extract through the filter medium commences and the consequentlowering level of liquid further increases the partial vacuum above thesame.

The air pressure in the space 15 and the liquid head 16 together equalatmospheric pressure at all times. However, as the liquid drains fromthe container 5, the head 16 decreases. Therefore, more air pressure hasto be admitted to the space continuously in order to compensate for thecontinuous loss of liquid. The ratio of the air pressure in the space 15to the liquid head 16 is inverse or indirect, since one gains as theother loses. To thus increase the pressure in the space 15, a constantstream of tiny air bubbles rises through the tube 14 during filtration.

It will be'apparent that in this manner, the head above the lower end ofthe gage tube is constantly balanced by the air pressure above the sameso that the only pressure under which the extract is forced to passthrough the filter cloth is that represented by the efi'ective head ofthe matter in the container below the lower end of the gage tube asindicated at 17 in the drawing. This condition is maintained until thecontinuously lowered level of the liquid falls below the end of the gagetube when the Vacuum is destroyed and the remainder of the liquid in thecontainer is discharged under atmospheric pressure. The rate offiltration is eontrolled by raising or lowering the gage tube 14. Thelarger the head 17, the faster the rate, the smaller the head, theslower the rate.

The device as shown and hereinabove described, is particularly adaptedfor use in making small uantities of coffee expeditiously and by t esimple process of placing hot water and ground coflee in the container,fastening the strainer across the mouth thereof and inverting the deviceover an ordinary cup or other suitable vessel.

The coffee extract passing through the interstices of the strainer isfree from impurities or solids as hereinbefore explained, principallyfor the reason that it is obtained in a gentle non-pulsating flowproduced under the restricted pressure of a predetermined lowhydrostatic head.

In case the capacity of the container-is greater than that of the vesselin which the extract is delivered, overflowing of the latter isprevented by discontinuance of the flow when the liquid in the vesseltouches the filter cloth, it being evident that the oil on the surfaceof the cloth and the air caught in the meshes of the same form a toughskin-friction that causes a resistance effectively opposing the pressureof the effective head in the container.

The wide mouth of the container and the absence of valves and othermovable parts permit of its being easily and thoroughly cleaned aftereach use.

Having thus described my invention What I claim and desire to secure byLetters Patent is 1. The method of making extracts consisting in causingliquid in an infusion to filter under a pressure less than atmospheric,automatically maintained in inverse ratio to the diminishing quantity ofunfiltered liquid in the infusion.

2. A device for making extracts comprising a container, a filter mediumat the bottom thereof, and means to automatically maintain a pressureless than atmospheric at the opposite end of the container, in indirectratio to a diminishing quantity of infusion in the container while theliquid in the infusion passes through the filter medium.

A device for making extracts comprising a container, a filter medium atan end thereof, a duct in the container having adjacent the filtermedium an opening in connection with the atmosphere, and 9. ga e adaptedto conduct air from adjacent sald opening to the space at the end of thecontainer opposite to that closed by the filter medium.

4. A device for making extracts comprising a container, a filter mediumclosing an end thereof, and an open-ended air duct having one leg in thecontainer, and its other leg outside the container.

5. A device for making extracts comprising a container, at filter mediumclosing an end thereof, and an open-ended air duct having one leg insidethe container with the end thereof adjacent the filter medium and havingits other leg outside the container in spaced relation to the wallthereof.

6'. A device for making extracts comprising a container, a filter mediumat an end thereof, a duct in the container having adjacent the filtermedium, an opening in connection with the atmosphere, and an open-endedtube connecting the interior of the duct adjacent said opening with thespace at the end of the container opposite that closed by the filtermedium.

7 A device for making extracts comprising a container, a filter mediumclosing an end thereof, a U-shaped air duct having one leg inside thecontainer with the end thereof adjacent the filter medium and having itsother leg outside the container, and an openended tube extending throughthe inside leg of the duct to conduct air entering the duct to a spaceat the end of thecontainer opposite to that closed by the filter medium.

8. A device for making extracts comprising a container, a filter mediumatthe bottom thereof, a duct extending downwardly in the container andhaving an opening adjacent the filter medium in connection with theatmosphere, and an open-ended tube in the duct to conduct air fromadjacent said opening to a space at the top of the container.

9. A device for making extracts comprising an otherwise closed containerhaving two openings, a filter medium at one opening, and an open-endedduct connecting the other opening with the duct within the containerterminating adjacent the filter medium.

10. In a device of the character described, the combination with areceiver, of a container closed at one end and provided at the oppositeend with a restraining surface apertured for the discharge of llquidfrom the container to the receiver, a duct in the container havingadjacent the restraining surface an opening in connection with theatmosphere and a gage adapted to conduct air from adj acent said openingto the space at the closed end of the container.

11. A device for making extracts comprising a container, a filteringmedium at an end thereof, an open-ended duct passing through the wall ofthe container, and havin an opening in the container between, the diumand the end of the container that is upw permost when the container isin an operative position.

12. The method of making extracts consistin'g'in producing anillfllSlOIl, and filtering atmosphere, the end of the ter me-' duringfiltration consisting in excluding atmospheric pressure from the surface.of the infusion and introducing air by atmospheric pressure at a pointbetween the surface of the infusion and the filter medium, a ainst thepressure above the point of intro notion of the air.

14. The method of controlling the rate and duration of flo-w of afiltrate from an in fusion, consisting in maintaining a partial vacuumat its surface, and introducing air at atmospheric pressure at a pointbelow its surface.

15. A device for making extracts comprising a container having anair-tight space at an end and having a filter opening at theoppositeend, and a duct having an open end adjacent the filter openingin connection with the atmosphere.

16. A device for making extracts comprising a container havin arestricted filter opening, and an open-en ed air duct having one leg inthe container and the other leg outside the same, the legs extending inthe same general direction.

17. A device for making extracts comprising a container having arestricted filter opening, and an open-ended air duct having one leg inthe container and the other leg outside the same, the legs beingapproximately the same length.

18. The method of making extracts consisting in filtering liquid under ahead of liquid and air pressure automatically maintained equal toatmospheric pressure while filtering.

In testimony-whereof I have aifixed my signature.

GEORGE W. TARKINGTON.

the same at a predetermined rate and dura tion of flow by excludingatmospheric pressure from the surface of the infusion and introducingair under ressure at a point between the surface 0 the infusion and the

